A proposal that all subdivided flats must have a window for ventilation purposes to comply with new minimum standards has met with opposition, the government said on Tuesday.

A public consultation exercise on a planned regulatory regime for subdivided flats ended on Monday, with thousands of submissions received.

Housing Secretary Winnie Ho told Commercial Radio that many of the submissions included concerns about the proposed window requirement, with some people suggesting that exhaust fans could be installed instead.

Ho said such a compromise would not be ideal.

"If there are no windows, would it feel like living in a cupboard?" she questioned.

"Even though we received suggestions during the consultation period saying 'let's not have windows and just install exhaust fans instead', I think windows are important to many people."

The government has suggested that windows that face an area enclosed on all four sides would not be good enough.

But Hayson Chan, who chairs a concern group for subdivided flat owners, said such windows could be complimented with an exhaust fan.

Ho said if the enclosed space is big enough or has good air quality, this restriction could be eased.

She said other feedback on the plans includes calls for a proposed 12 to 24-month grace period for owners to get their flats up to scratch to be extended to 36 months.